In today's information age, communication devices, such as computers and computer peripherals, are often internetworked over a communication network. For various reasons, it is sometimes necessary or desirable for the communication network to be shared by multiple consumers. Because each of the consumers typically needs to maintain a certain amount of autonomy, the communication network is divided into a number of Virtual Private Networks (VPNs), where each VPN emulates a single, private network.
Various mechanisms for supporting VPNs in an MPLS environment are described in the IETF Internet Draft documents entitled VPN SUPPORT WITH MPLS [draft-heinanen-mpls-vpn-01.txt (March 1998)], MPLS VPN ARCHITECTURE [draft-jamieson-mpls-vpn-00.txt (August 1998)], IP VPN REALIZATION USING MPLS TUNNELS [draft-casey-vpn-mpls-00.txt (November 1998)], and CPE BASED VPNS USING MPLS [draft-li-mpls-vpn-00.txt], all of which are hereby incorporated by reference in their entireties.